温度对IMO-SBR脱氮途径的影响研究

将微生物固定化技术与SBR工艺相结合,开发出IMO-SBR (immoblization organism-sequencing batch reaotor)生物强化工艺处理含氮废水.采用IMO-SBR和普通活性污泥SBR工艺进行废水处理的对比实验,研究了不同温度条件下微生物的脱氮途径以及温度对脱氮途径的影响,得出了通过控制温度使反应器内微生物在好氧条件下发生同步硝化反硝化(SND)是可行的结论,为固定化微生物技术的工业化应用提供了一定的参考依据.     

CAST工艺强化脱氮的设计改进

针对CAST工艺脱氮效率及同步硝化反硝化受碳源、生物絮体大小、溶解氧等因素的影响,以华北某污水处理厂为研究对象,结合污水处理厂运行现状,比较了CAST工艺强化脱氮等不同方案,提出了采用AO/SBR工艺作为该污水处理厂的升级改造工艺。运行结果表明,出水水质可以达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级B标准。     

焦化废水生物脱氮技术研究进展

焦化废水是一种氨氮和有机物浓度较高的难生化降解的有机废水,本文介绍了近年来焦化废水生物脱氮处理技术的特点及研究进展,包括传统的硝化反硝化工艺及新型的短程硝化反硝化、同时硝化反硝化以及厌氧氨氧化工艺,最后指出目前生物脱氮研究的主要方向。     

低C/N比异养硝化-好氧反硝化菌筛选及硝化特性

针对生物法处理低C/N比废水存在碳源不足、脱氮效率不高问题,从石化废水处理厂活性污泥中分离得到一株低C/N比异养硝化-好氧反硝化菌株WUST-7。通过形态学观察、生理生化试验和16S rDNA序列分析,鉴定其为假单胞菌属（Pseudomonas sp.）。通过单因素实验,考察碳源种类、培养温度、初始pH和摇床转速对菌株硝化性能的影响,确定最优异养硝化培养条件为：丁二酸钠为碳源、培养温度30～35℃、初始pH8.0～9.0、摇床转速150～200r/min。在最优异养硝化条件下培养9h,可将初始浓度为107.52mg/L的氨氮去除90.64%,并且在整个培养过程中没有亚硝酸盐氮的积累,硝酸盐氮含量也始终低于3.5mg/L,总氮的去除率达88.63%。实验结果表明,菌株WUST-7在利用氨氮进行硝化反应的同时,还可以利用硝酸盐氮进行反硝化,具有良好的同步硝化反硝化潜能。     

基于硫循环的污水处理工艺——SANI工艺研究进展

硫酸盐还原、自养反硝化和硝化集成工艺(sulfate reduction,autotrophic denitrification and nitrification integrated,SANI)是一种基于硫循环、低污泥产出的污水处理新工艺。该工艺不仅可实现去除有机物、脱氮、消毒等水处理要求,还从源头上解决了污水处理产生大量污泥的问题。对SANI工艺及其改型工艺的起源、形式、原理、研究现状进行了详细综述,对该工艺存在的问题进行了分析,并对未来研究方向进行了展望,以期为污水处理行业的发展提供新思路。     

改良UCT分段进水脱氮除磷工艺性能及物料平衡

采用改良UCT分段进水试验装置研究了该工艺处理实际生活废水的脱氮除磷性能,建立了该系统碳(COD)、氮、磷的物料衡算公式,并以稳态条件下试验数据为基础分析评价了各指标的物料分布情况。结果表明,工艺出水水质稳定,抗冲击负荷能力较强,平均出水COD、总氮、总磷含量分别为43.5、8.51、0.29mg·mL-1,满足国家城镇生活污水一级A排放标准。此外,根据建立的物料衡算公式及工艺各反应区污染物指标的转化途径分析发现,高达67.1%的反硝化脱氮作用(包括缺氧反硝化和好氧同步硝化反硝化)是该工艺深度脱氮的根本原因;系统反硝化和释磷过程利用的COD占总去除量的62.1%,体现了该工艺充分利用原水碳源的优势;氮素和COD的平衡率均高达99.8%,证明了所建立的公式的有效性。系统对磷的去除主要依赖于排放的剩余污泥,占总量的71.7%。     

Development of a correlation to study parameters affecting nitrification in a domestic wastewater treatment plant

BACKGROUND: Nitrification performance of an activated sludge reactor treating weak domestic wastewater was investigated for 11 months. Ammonia nitrogen removals were investigated as a function of wastewater composition and operational conditions. Backward elimination experimental design was used to determine the influence of the most important independent variables on NH₃‐N removal efficiencies. Influent ammonia and biological oxygen demand (BOD₅) concentrations, hydraulic retention time (HRT), mixed liquid suspended solids (MLSS), temperature, pH and dissolved oxygen (DO) concentration were considered as independent variables. This study aimed to find the most important parameters to describe nitrification performance. RESULTS: The presence of nitrification was confirmed by ammonia and nitrate variations throughout the reactor; ammonia oxidizing bacteria (AOB) populations were determined using a fluorescence in situ hybridization (FISH) method. MLSS concentration, influent BOD₅ concentration and temperature were found to be the most influential factors on nitrification performance. The empirical correlation using multiple linear regressions was statistically significant and produced an adjusted coefficient of multiple determinations (R²_adj) of 92.5%. CONCLUSION: Correlation provides a good understanding of the various parameters that affect the nitrification process, and could be extended to other case studies. Using these results, operators can apply proper operational strategies to maintain nitrification in wastewater treatment plants. Copyright © 2007 Society of Chemical Industry     

Mathematical modeling of aerobic membrane bioreactor (MBR) using activated sludge model no. 1 (ASM1)

Activated sludge model no. 1 (ASM1) was applied to an aerobic membrane bioreactor (MBR) treating dilute municipal wastewater. The model for the aerobic MBR was calibrated using the data collected from a lab-scale aerobic MBR using AQUASIM 2.0. The performance of MBR process in terms of chemical oxygen demand (COD) removal and ammonia nitrogen (SNH) nitrification was studied at different operating conditions such as hydraulic retention time (HRT), solid retention time (SRT) and mixed liquor suspended solids (MLSS) concentrations. The characteristics of influent wastewater, pre-settled primary effluent from a wastewater treatment plant (City of Elmhurst WWTP, Elmhurst, IL, USA), were determined in the laboratory and used for the calibration of the model. The results from the simulations provided a better understanding of the mechanisms and kinetics of the MBR process including sludge removal.     

高浓度氨氮废水脱氮技术研究进展

结合高浓度氨氮废水的特点,评述了主要的氨氮处理技术,包括折点氯化法、吹脱法、选择性离子交换法、化学沉淀法及传统生物脱氮技术,同时还评述了硝化反硝化、亚硝酸型硝化反硝化、厌氧氨氧化以及亚硝酸型硝化一厌氧氨氧化等新型生物脱氮技术,介绍了它们的处理原理、研究现状、适宜条件和需要解决的问题.同时指出了高浓度氨氮废水处理技术今后的发展方向.     

Sequenced aeration in a membrane bioreactor: Specific nitrogen removal rates

The aim of this work was to quantify the activity of autotrophic and heterotrophic populations present in a submerged membrane bioreactor submitted to a sequenced aeration, ensuring alternate nitrification and denitrification (BIOSEP® process). Specific nitrification and denitrification rates were determined over a fifteen‐month running period, with and without physico‐chemical phosphorus removal. The results show (i) zero‐order kinetics; (ii) a specific activity independent of MLVSS concentration; and (iii) an evolution of the nitrification kinetics directly linked to an evolution of the nitrifying population within the unit. The study confirmed that denitrification kinetics depend on the concentration and on the nature of wastewater organic matter.     

Integration of continuous biological and chemical (ozone) treatment of domestic wastewater: 1. Biodegradation and post‐ozonation

The continuous treatment of domestic wastewater by an activated sludge process and by an integrated biological–chemical (ozone) oxidation process were studied in this work. Chemical oxygen demand (COD), biochemical oxygen demand (BOD), absorbance at 254 nm (UV₂₅₄) and nitrogenous compound content were the parameters followed in order to evaluate the performance of the two processes. Experimental data showed that both UV₂₅₄ and COD reductions are improved in the combined biological–chemical oxidation procedure. Thus, reductions of 59.1% and 37.2% corresponding to COD and UV₂₅₄, respectively were observed after the biological process (hydraulic retention time = 5 h; mixed liquor volatile suspended solids concentration = 3142 g m⁻³) compared with 71.0% and 78.4% obtained when a post‐ozonation step ( D _O3 = 41.7 g m⁻³) was included. During conventional activated sludge treatment, appropriate nitrification levels are only achieved with high hydraulic retention time and/or biomass concentration. Ozonation after the secondary treatment, however, allows improved nitrogen content reduction with total nitrite elimination. Post‐ozonation also leads to a higher biodegradability of the treated wastewater. Thus, the ultimate BOD/COD ratio goes from 0.16 after biological oxidation to 0.34 after post‐ozonation with 41.7 g O₃ m⁻³. © 1999 Society of Chemical Industry     

野生型嗜盐混合菌群处理高盐生活污水的硝化性能

由于渗透压和无机盐生物毒性的影响,淡水活性污泥无法在高盐环境下进行正常的新陈代谢。生物处理高盐废水受到极大的挑战。为了解决这一难题,本研究采集入海口河底泥培养嗜盐活性污泥,并考察了该污泥的硝化性能。研究采用实际高盐生活污水探讨了嗜盐处理系统的启动、氨氮负荷和盐度冲击对系统硝化的影响。实验结果表明：经过9 d适应期,嗜盐污泥开始硝化高盐生活污水中的氨氮。氨氮负荷及其负荷的稳定性对氨氮去除率具有显著影响。研究确定了嗜盐硝化系统的耐盐范围为10～60 g·L^-1,而最优盐度在40 g·L^-1左右。由于该嗜盐混合菌群是由海洋菌和中度嗜盐菌组成的,该系统具有良好的抗盐度冲击能力和硝化活性。尽管实验采用的操作条件不会对亚硝酸氧化菌构成抑制,但是研究中却发现显著的亚硝酸盐积累现象。该研究为实现高盐废水生物处理提供了有益探索。     

Effects of Operational Variables on Nitrogen Removal Performances and Its Control in a Pre‐Denitrification Plant

The aim of this work is to study the effects of six operational variables, i.e., dissolved oxygen (DO), nitrate recirculation flow, sludge recycle flow, sludge wastage flow, external carbon dosage, and anoxic volume fraction, on the performance of nitrogen removal and its control in a pre‐denitrification plant. The results obtained show that the six operational variables have a significant influence on nitrogen removal in such a system, while the utilization of the control strategies can improve the situation to a significant extent. The control of DO concentration should be correlated with the influent ammonia load, the effluent requirement and nitrification type. The anoxic effluent nitrate concentration should be controlled at ca. 2 mg/L or the ORP value at the end of the anoxic zone should be controlled at ca. –90 mV. The control of the sludge recycling flow by online monitoring of the sludge blanket height (SBH), is an alternative to the conventional control of the constant sludge recycle flow. It may be possible to achieve the automatic control of sludge wastage flow by online measuring of the ammonia concentration and the nitrification capacity of the sludge. The recirculation of nitrate and external carbon dosage should be simultaneously controlled to optimize nitrogen removal. The anoxic volume fraction should also be optimized, to ensure a good balance between nitrification and denitrification.     

Development of a mechanistic model for biological nutrient removal activated sludge systems and application to a full‐scale WWTP

In wastewater treatment plants (WWTPs) the production of nitrite as an intermediate in the biological nutrient removal (BNR) process has been widely observed, but not been taken into account by most of the conventional activated sludge models yet. This work aims to develop a mechanistic mathematical model to evaluate the BNR process after resolving such a problem. A mathematical model is developed based on the Activated Sludge Model No.3 (ASM3) and the EAWAG Bio‐P model with an incorporation of the two‐step nitrification–denitrification, the anoxic P uptake, and the associated two‐step denitrification by phosphorus accumulating organisms. The database used for simulations originates from a full‐scale BNR municipal wastewater treatment plant. The influent wastewater composition is characterized using batch tests. Model predictions are compared with the measured concentrations of chemical oxygen demand (COD), NH‐N, NO‐N, NO‐N, PO‐P, and mixed liquid volatile suspended solids. Simulation results indicate that the calibrated model is capable of predicting the microbial growth, COD removal, nitrification and denitrification, as well as aerobic and anoxic P removal. Thus, this model can be used to evaluate and simulate full‐scale BNR activated sludge WWTPs. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

高效生物硝化工艺研究进展

高效生物脱氮工艺是废水处理领域的研究热点,生物硝化是废水生物脱氮工艺的重要环节,也是废水去除氨氮的有效手段。国内外研究人员先后开发了全程硝化工艺、全量短程硝化工艺和半量短程硝化工艺等高效生物硝化工艺,有力推动了废水生物脱氮技术的发展。综述了全程硝化工艺、全量短程硝化工艺和半量短程硝化工艺的原理、性能和操作等内容,对各工艺的特征和优势进行了比较,以期为高效生物硝化工艺的研发和应用提供借鉴。     

提高氧化沟对炼油污水氨氮去除效果的探讨

通过监测数据发现,某炼油公司炼油污水处理场氧化沟系统对有机污染物（COD和BOD）的去除效果较理想,但对氨氮则没有降解效果。从硝化作用（氨氮降解）和反硝化作用（脱氮）的原理出发,分析了氧化沟系统对氨氮降解差的原因,并提出了相应的解决措施。     

污水处理厂循环式硝化脱氮法设计与运行管理

污水再利用日益受到重视,需对污水处理厂实施改造,以达到高效除磷脱氮的目的,并提高出水水质。污水处理工艺循环式硝化脱氮法的设计程序中,需对SRT和A-SRT、MLSS浓度和循环比以及二沉池负荷等运行指标进行设定。在运行管理过程中,需对缺氧池的氧化还原电位以及好氧池的溶解氧浓度等数据进行把控。通过改造标准活性污泥法的设施、在曝气池中增设隔墙、设置DO计和ORP计的信息反馈系统等,使之成为污水脱氮的高级处理设施,满足处理水回收再利用的水质要求。     

AO工艺同步脱氮除磷效能的研究

采用A／O同步脱氮除磷工艺处理模拟污水,调整DO、HRT、内回流、进水污染物的浓度等影响因素,考察了该工艺单位活性污泥处理污水中TN、TP的能力。结果表明,当好氧区DO控制在0．6mg／L左右,HRT控制在10h,内回流比控制在1：1时,单位活性污泥处理污水TN、TP的能力最强,单位活性污泥TN去除速率达到14×10^-3mg／（L·mg MLVSS·h）,单位活性污泥TP去除速率达到0．14×10^-3mg／（L·mg MLVSS·h）,AO系统实现了同步硝化反硝化和反硝化除磷。     

抗生素废水深度处理全流程试验研究

采用厌氧水解(酸化)预处理-两段生物接触氧化脱氮-改性粉煤灰脱色除磷-粉煤灰稳定剩余污泥工艺进行抗生素生产废水的综合治理。试验表明本工艺是可行的,这为解决高浓度抗生素生产废水提供了一条新的治理途径．